Idling rpm regulation in an internal combustion engine serves to keep the rpm as low as possible during idling for the sake of minimal fuel consumption, while nevertheless assuring that the engine will not stall in the event of any fluctuations in the load. A great number of idling regulating devices have already become known. German Offenlegungsschrift No. 27 49 369, for instance, describes an idling regulation system having a magnetic valve in the throttle bypass, the cross section of which is regulated in accordance with the deviation of the actual rpm value from the set-point rpm value. The set-point rpm value is based on operating characteristics, such as the engine temperature.
An improvement in the system known from German Offenlegungsschrift No. 27 49 369 is taught in German Pat. No. 26 32 613, according to which the position of the bypass cross section control device itself is supposed to be regulated.
It has now been demonstrated that even with known, improved idling regulation systems, optimal results are still not attainable. This is because even the position of the bypass cross section control device per se still does not furnish reliable information as to the operation of the final control element.